Alert archive / Utah / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 21, NWS Salt Lake City, UT

July 20, 2017Carbon County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Jul 20, 2017, 4:33 PM MDT for Carbon County, Utah. It was in force for 27 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 20, 2017, 4:33 PM MDT (22:33 UTC)
Expired: Jul 20, 2017, 5:00 PM MDT
In force: 27 min
Issued by: NWS Salt Lake City, UT
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Carbon County, UT

The radar

The Grand Junction radar (KGJX), 178 km from the middle of the area, began a volume at 22:34 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Grand Junction, CO (KGJT), launched 12:00Z, 10.6 hours before the alert went out and 153 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 112 J/kg
Mixed-layer CIN: -333 J/kg
Mixed-layer LCL: 1730 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 127 m²/s²
0-3 km storm-relative helicity: 177 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

771 
WUUS55 KSLC 202233
SVRSLC
UTC007-202300-
/O.NEW.KSLC.SV.W.0021.170720T2233Z-170720T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
433 PM MDT THU JUL 20 2017

The National Weather Service in Salt Lake City has issued a

* Severe Thunderstorm Warning for...
  Northeastern Carbon County in central Utah...

* Until 500 PM MDT

* At 432 PM MDT, a severe thunderstorm was located 25 miles south of
  Myton, or 29 miles southeast of Duchesne, moving northeast at 25
  mph.

  HAZARD...60 mph wind gusts and quarter size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees. 

* This severe thunderstorm will remain over mainly rural areas of
  northeastern Carbon County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3974 10999 3976 11023 3981 11022 3981 11011
      3980 10998 3980 10997
TIME...MOT...LOC 2232Z 221DEG 23KT 3983 11008 

HAIL...1.00IN
WIND...60MPH
 
$$

CRK

1 follow-up statement

448 
WWUS55 KSLC 202243
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
443 PM MDT THU JUL 20 2017

UTC007-202300-
/O.CON.KSLC.SV.W.0021.000000T0000Z-170720T2300Z/
Carbon UT-
443 PM MDT THU JUL 20 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM MDT
FOR NORTHEASTERN CARBON COUNTY...

At 443 PM MDT, a severe thunderstorm was located 21 miles south of
Myton, or 28 miles southeast of Duchesne, moving northeast at 25 mph.

HAZARD...60 mph wind gusts and quarter size hail. 

SOURCE...Radar indicated. 

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees. 

This severe thunderstorm will remain over mainly rural areas of
northeastern Carbon County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3975 11016 3981 11016 3981 11011 3980 10998
      3980 10997 3974 10999
TIME...MOT...LOC 2243Z 221DEG 23KT 3988 11002 

HAIL...1.00IN
WIND...60MPH
 
$$

CRK

The office that day

Everything else NWS Salt Lake City, UT issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 20, 3:08 AM MDT	Flash Flood Watch	SLC		21 hr
Jul 20, 4:23 PM MDT	Severe Thunderstorm Warning	SLC	Duchesne	37 min
Jul 20, 4:56 PM MDT	Special Weather Statement	SLC	Carbon	34 min

Nearby

Severe Thunderstorm Warnings in Utah, 2017 Every severe thunderstorm warning in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.